Principles of Chemistry IGCSE Edexcel (States of Matter Pt. 1.1-1.4)

Three states of matter

Solids, liquids and gases

Arrangement of solids

Regular arrangement and vibrate in fixed positions

Arrangement of gases

Random arrangement and move quickly in all directions

Interconversion of state

- A physical change involving changes in forces between particles of a substance

Evaporation

• Occurs at surface of liquids

• High energy particles escape

• Occurs over a range of temperatures

Boiling

• Requires heat energy (which is transformed into kinetic energy)

• Occurs at a specific temperature unique to each pure liquid

Melting

• Requires heat energy (which is transformed into kinetic energy)

• Occurs at a specific temperature unique to each pure solid

Freezing

• Reverse of melting

• Happens at the exacts same temperature as melting

Condensation

• Gas to liquid

• Particles lose energy and group together instead of bouncing away when they bump into each other

Solvent

Liquid in which solute dissolves

Solute

Substance that dissolves in a liquid to form a solution

Saturated solution

A solution with the maximum concentration of solute dissolved in the solvent

Element

A substance made up from only one type of atom

Compound

A substance made from two or more elements that are chemically bonded together

Mixture

Two or more elements or compounds physically combined together

Simple distillation

Separating a solvent from a solution

Fractional distillation

Separating a liquid from a mixture of liquids

Paper chromatography

Separating mixtures of soluble substances (Eg. Inks)

Rf value

Distance travelled by solute / solvent front

Proton

• relative mass is 1

• relative charge is +1

• found in nucleus

Neutron

• relative mass is 1

• relative charge is 0 . Found in nucleus

Electron

• relative mass is almost 0

• charge is -1

• found in shells

An Isotope

• same element

• same number of protons

• different number of neutrons

Relative atomic mass

(Mass of isotope 1 x % of isotope)+(mass of isotope 2 x % of isotope 2)+(mass of isotope 3 x % of isotope 3)ect.
All divided by 100